[ios] Adds code for Omaha and the upgrade center.

ios/chrome/browser/omaha/omaha_service.h

+// Copyright 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef IOS_CHROME_BROWSER_OMAHA_OMAHA_SERVICE_H_
+#define IOS_CHROME_BROWSER_OMAHA_OMAHA_SERVICE_H_
+
+#include <memory>
+
+#include "base/callback.h"
+#include "base/gtest_prod_util.h"
+#include "base/macros.h"
+#include "base/memory/singleton.h"
+#include "base/scoped_observer.h"
+#include "base/timer/timer.h"
+#include "base/version.h"
+#include "net/url_request/url_fetcher_delegate.h"
+
+namespace base {
+class DictionaryValue;
+}
+
+namespace net {
+class URLFetcher;
+class URLRequestContextGetter;
+}
+
+struct UpgradeRecommendedDetails;
+
+// This service handles the communication with the Omaha server. It also
+// handles all the scheduling necessary to contact the server regularly.
+// All methods, but the constructor, |GetInstance| and |Start| methods, must be
+// called from the io thread.

[sdefresne, 2016/12/14 11:50:55]

nit: io -> IO

[rohitrao (ping after 24h), 2016/12/14 13:26:32]

Done.

+class OmahaService : public net::URLFetcherDelegate {
+ public:
+  // Called when an upgrade is recommended.
+  using UpgradeRecommendedCallback =
+      base::Callback<void(const UpgradeRecommendedDetails&)>;
+
+  // Start the service. Also set the |URLRequestContextGetter| necessary to

[sdefresne, 2016/12/14 11:50:55]

Should it be "Starts" (I'm terrible at English grammar, but the other comments
use the "s" form of the verbs)?

[rohitrao (ping after 24h), 2016/12/14 13:26:32]

Done.

+  // access the Omaha server. This method should only be called once.
+  static void Start(net::URLRequestContextGetter* request_context_getter,
+                    const UpgradeRecommendedCallback& callback);
+
+  // Returns debug information about the omaha service.
+  static void GetDebugInformation(
+      const base::Callback<void(base::DictionaryValue*)> callback);
+
+ private:
+  // For tests:
+  friend class OmahaServiceTest;
+  friend class OmahaServiceInternalTest;
+  FRIEND_TEST_ALL_PREFIXES(OmahaServiceTest, PingMessageTest);
+  FRIEND_TEST_ALL_PREFIXES(OmahaServiceTest,
+                           PingMessageTestWithUnknownInstallDate);
+  FRIEND_TEST_ALL_PREFIXES(OmahaServiceTest, InstallEventMessageTest);
+  FRIEND_TEST_ALL_PREFIXES(OmahaServiceTest, SendPingFailure);
+  FRIEND_TEST_ALL_PREFIXES(OmahaServiceTest, SendPingSuccess);
+  FRIEND_TEST_ALL_PREFIXES(OmahaServiceTest, SendInstallEventSuccess);
+  FRIEND_TEST_ALL_PREFIXES(OmahaServiceTest, SendPingReceiveUpdate);
+  FRIEND_TEST_ALL_PREFIXES(OmahaServiceTest, PersistStatesTest);
+  FRIEND_TEST_ALL_PREFIXES(OmahaServiceTest, BackoffTest);
+  FRIEND_TEST_ALL_PREFIXES(OmahaServiceTest, NonSpammingTest);
+  FRIEND_TEST_ALL_PREFIXES(OmahaServiceTest, ActivePingAfterInstallEventTest);
+  FRIEND_TEST_ALL_PREFIXES(OmahaServiceTest, InstallRetryTest);
+  FRIEND_TEST_ALL_PREFIXES(OmahaServiceInternalTest,
+                           PingMessageTestWithProfileData);
+  // For the singleton:
+  friend struct base::DefaultSingletonTraits<OmahaService>;
+  friend class base::Singleton<OmahaService>;
+
+  // Enum for the |GetPingContent| and |GetNextPingRequestId| method.
+  enum PingContent {
+    INSTALL_EVENT,
+    USAGE_PING,
+  };
+
+  // Initialize the timer. Used on startup.
+  void Initialize();
+
+  // net::URLFetcherDelegate
+  void OnURLFetchComplete(const net::URLFetcher* fetcher) override;
+
+  // Raw GetInstance method. Necessary for using singletons.
+  static OmahaService* GetInstance();
+
+  // Private constructor, only used by the singleton.
+  OmahaService();
+  // Private constructor, only used for tests.
+  explicit OmahaService(bool schedule);
+  ~OmahaService() override;
+
+  // Returns the time to wait before next attempt.
+  static base::TimeDelta GetBackOff(uint8_t number_of_tries);
+
+  void set_upgrade_recommended_callback(
+      const UpgradeRecommendedCallback& callback) {
+    upgrade_recommended_callback_ = callback;
+  }
+
+  // Send a ping to the Omaha server.

[sdefresne, 2016/12/14 11:50:55]

"Sends"?

[rohitrao (ping after 24h), 2016/12/14 13:26:32]

Done.

+  void SendPing();
+
+  // Method that will either start sending a ping to the server, or schedule
+  // itself to be called again when the next ping must be send.
+  void SendOrScheduleNextPing();
+
+  // Persisting states of the service.

[sdefresne, 2016/12/14 11:50:55]

"Persists state of the service."?

[rohitrao (ping after 24h), 2016/12/14 13:26:32]

Done.

+  void PersistStates();
+
+  // Returns the xml representation of the ping message to send to the Omaha
+  // server. If |sendInstallEvent| is true, the message will contain an
+  // installation complete event.
+  std::string GetPingContent(const std::string& requestId,
+                             const std::string& sessionId,
+                             const std::string& versionName,
+                             const std::string& channelName,
+                             const base::Time& installationTime,
+                             PingContent pingContent);
+
+  // Returns the xml representation of the ping message to send to the Omaha

[sdefresne, 2016/12/14 11:50:55]

nit: XML

[rohitrao (ping after 24h), 2016/12/14 13:26:32]

Done.

+  // server. Use the current state of the service to compute the right message.
+  std::string GetCurrentPingContent();
+
+  // Computes debugging information and fill |result|.
+  void GetDebugInformationOnIOThread(
+      const base::Callback<void(base::DictionaryValue*)> callback);
+
+  // Returns whether the next ping to send must a an install/update ping. If
+  // |true|, the next ping must use |GetInstallRetryRequestId| as identifier
+  // for the request and must include a X-RequestAge header.
+  bool IsNextPingInstallRetry();
+
+  // Returns the request identifier to use for the next ping. If it is an
+  // install/update retry, it will return the identifier used on the initial
+  // request. If this is not the case, returns a random id.
+  // |send_install_event| must be true if the next ping is a install/update
+  // event, in that case, the identifier will be stored so that it can be
+  // reused until the ping is successful.
+  std::string GetNextPingRequestId(PingContent ping_content);
+
+  // Stores the given request id to be reused on install/update retry.
+  void SetInstallRetryRequestId(const std::string& request_id);
+
+  // Clears the stored request id for a installation/update ping retry. Must be
+  // called after a successfull installation/update ping.
+  void ClearInstallRetryRequestId();
+
+  // Clears the all persistent state. Should only be used for testing.
+  static void ClearPersistentStateForTests();
+
+  // To communicate with the Omaha server.
+  std::unique_ptr<net::URLFetcher> fetcher_;
+  net::URLRequestContextGetter* request_context_getter_;  // weak

[sdefresne, 2016/12/14 11:50:55]

Remove "// weak" (if it were strong, then a std::unique_ptr<> or shared_ptr<>
would be used).

[rohitrao (ping after 24h), 2016/12/14 13:26:32]

Done.

+
+  // The timer that call this object back when needed.
+  base::OneShotTimer timer_;
+
+  // Whether to schedule pings. This is only false for tests.
+  const bool schedule_;
+
+  // The install date of the application.  This is fetched in |Initialize| on
+  // the main thread and cached for use on the IO thread.
+  int64_t application_install_date_;
+
+  // The time at which the last ping was sent.
+  base::Time last_sent_time_;
+
+  // The time at which to send the next ping.
+  base::Time next_tries_time_;
+
+  // The timestamp of the ping to send.
+  base::Time current_ping_time_;
+
+  // Last version for which an installation ping has been sent.
+  base::Version last_sent_version_;
+
+  // The language in use at start up.
+  std::string locale_lang_;
+
+  // Number of tries of the last ping.
+  uint8_t number_of_tries_;
+
+  // Whether the ping currently being sent is an install (new or update) ping.
+  bool sending_install_event_;
+
+  // Called to notify that upgrade is recommended.
+  UpgradeRecommendedCallback upgrade_recommended_callback_;
+
+  DISALLOW_COPY_AND_ASSIGN(OmahaService);
+};
+
+#endif  // IOS_CHROME_BROWSER_OMAHA_OMAHA_SERVICE_H_